Fisher CZ Forum

I found a CZ6 last year at a pawn shop for a fairly reasonable amount because of my love for my hot as Hades CZ5. I immediately noticed that in spite of the similarity with the CZ5, there was no speaker and with it's rubber covering on the salt/normal switch and on the 1/4" phones jack (yes, as I found out later, it is the converted model CZ6A) I checked to see if it came on and it reacted to the showcase in the pawn shop so I assumed it was fine and went ahead and bought it. It's a Fisher CZ after all, right? After having it almost a year, basically mothballed as a backup, since I am very familiar with the my particular CZ5 and always use it with the attached FZ-1 Sun Ray Intruder probe, I took it along on a trip to see the eclipse, intending for a friend to use it and found that it wasn't working! It came on but would function. I came home and set it aside. I fiddled with it a little and swapped coils, (I have two 8" and a 5" loop) but got nowhere. Being a licensed HAM (KD5SRG) I decided to open it up and have a look. I quickly found the problem but I am afraid that I found more than that! In addition to the issue at hand, which was a simple, (a slight dislodging of the secondary board from the main board, I guess I had dropped it or it somehow took a jolt and one of the nylon stand-offs wasn't seated, thus one of the 6 pin headers wasn't seating all the way) I had a real mess in there! The work done during conversion was HORRIBLE but I cleaned things up as much as I could and reassembled it to find I was correct about the connectors being unseated. It is working again but the depth is miserably shallow, like maybe 2 inches on a dime and no apparent modulated audio. I get a loud ping or I get nothing. ID seems to be OK but sensitivity is gone. As for the conversion, I really have my doubts that this was done by the factory! HORRIBLE solder work and destruction of traces. They must've used a 1000 watt soldering iron! Shoddy work on the coil connector wires and spooged RTV! A ridiculous excuse for electronics work! However looking at the original joints on the tuning pots, they show a strange, burned appearance as well. I may need to go over and properly re-solder everything! Or just punt and move on. Any idea whether I should send it to Fisher or to NASA Tom? BTW, I did test the coils. I tried on them all with my CZ5 and they work beautifully on it, 10" minimum on a dime and 14" to 15" on the 1893 Colombian Expo silver half I found. Here's the ugly sights I found inside this poor CZ6A! I hope it's not too far gone! What do you think and what would you do?

QuoteElton
I myself would not put anymore money in it... It's a very early 90's detector that WILL cost a lot for repair.

The fact that it's an early 90's detector has nothing to do with it. You should know that if you own a CZ. My CZ5 will kick the ass of 95% of modern detectors and it's easily 5 years older than this CZ6(A). It doesn't necessarily need repair, it is working. What it is likely in need of is re-tuning, since I feel that is what is mainly wrong with the function of the unit. I can't very well dump it on anyone, it won't make anyone a good machine without some depth. I wonder that a re-tune might at least make it a usable machine. It can't cost that much. I got it for a good deal. As long as I don't put any more than a decent one into it, I'm good. I can't imagine it would make it any worse unless they botch the re-tune.

In the photos it looks like there may be PC board contamination. That'd kill the differentiators and sample-and-holds. The customary cure for PC board contamination is washing with isopropyl alcohol. And like all medicines, it doesn't always work.

QuoteDave J.
In the photos it looks like there may be PC board contamination. That'd kill the differentiators and sample-and-holds. The customary cure for PC board contamination is washing with isopropyl alcohol. And like all medicines, it doesn't always work.

I think the worst contamination to hit these boards was the tech that did the conversion! ;-) Horrible work! I have some De-oxy and several versions of alcohol, denatured, isopropyl and ethanol. (My favorite being Stolichnaya!) I will give it a go over after I sample some things to see which one does the trick. I have some old hand wired Dynaco amps that have undergone PCB contamination but they are MUCH worse. I think I should be OK here. i may go over it with some 60/40 silver solder and send it to NASA tom for re-alignment. Wouldn't this be a good way to show off his abilities to bring these old babies into service even after abuse such as this! I may see about trying to improve on what was done by this obviously heavy handed tech! While i'm at it I may be able to re-solder and remove all of that corrosion from the multitude of pots (not necessarily in that order) that seem to look dark and crusty and might even be able to improve on the lousy trace repairs done to this poor metal detector, all done to overcome the despicable decision to use silly plastic connectors and phone connectors to fit headphones that normally adapt to every other detector in existence! Must've been during Fisher's "dark" years.

Tom don't repair he just retunes...I guess a call to him would not hurt....or if you have the tools and time a resolder job might do the trick...its vintage late 91 or 92 if your wondering how old it is...Original CZ6 wasn't manufactured for a long period of time and replaced by the CZ6A ....

Sounds like my CZ6a. Many years back, it suddenly lost depth, and just like yours, a dime gets detected at 1 ".
Did nothing to it, did not drop it, dunked in water,.... Sent it back to Fisher. They repaired it under warranty, but never explained to me why. When questioned, the only answer was they replaced a resistor. But it's been working now for over 10 years.

So, I don't believe it's a retune thing...out of tune will not make it lose all detecting depth, JMHO.